Methods and apparatus for metal rolling



Dec. 29, 1970 r A, FOX ET AL 3,550,419

METHODS AND APPARATUS FOR METAL ROLLING Filed March 4. 1968 v.-. v -lFig.3.

United States Patent O 3,550,419 METHODS AND APPARATUS FOR METAL ROLLINGThomas A. Fox and Joseph Zentko, both Fox Industries, Inc., Box 358,Youngstown, Ohio 44401 Filed Mar. 4, 1968, Ser. No. 710,027 Int. Cl.B21b 11/00 U.S. Cl. 72-199 4 Claims ABSTRACT F THE DISCLOSURE A methodand apparatus for metal rolling by introducing vibrational force into atleast one roll outside the bearings.

This invention relates to methods and apparatus for metal rolling andparticularly methods and apparatus for introducing vibrating force intothe working rolls of a metal rolling mill to improve the rate ofreduction and the quality of the product.

The art of rolling metals has been faced with the constant problem ofincreasing the speed and the quality of rolling. These two desired endsare frequently inconsistent and the industry has been continually besetwith problems in its attempts to attain these ends.

We have discovered that we can improve both the speed and quality of therolling by imparting a vibrating force into the mechanism of the rollingmill or roll forming line. We have found that when one or both of theWork rolls is vibrating, the work moves more freely and the resistancein the mill is reduced. This means that a greater reduction of metal can-be achieved by any given unit of force. The quality of the product isimproved because of greater uniformity in thickness and a reduction inthe strains induced by the mill.

We believe that the surprising effectiveness of our invention resides inan effect similar to that of forging combined with the rollingoperation, thus with a prearranged frequency of vibration in a workroll, the metal being rolled is not only rolled in the conventional way,but is simultaneously hammered into itself. This we believe reduces theresistance and strain in both the mill and the work by reducing thepulling and stretching action of the mill required to produce a givenreduction.

We have found that the manner of introduction of the vibrating force isimportant. We have found that the vibrating force cannot be introducedinto the mill through the roll journals and bearings because thebearings are destroyed and the net efficiency is low. We have found thatthe vibration can be best introduced through the use of a roll ofmagnastrictive material operating in a pulsating magnetic field thuscausing the roll to expand and contract as it rolls.

In a preferred embodiment of our invention we provide in a rolling millhaving a housing, a plurality of rolls journaled for rotation in saidhousing, at least o'iie of said rolls being on each side of a pass line,and means for introducing vibrational force into at least one of saidrolls outside the bearings to impart the sarne to a work piece in saidpass line. Preferably, at least one of said rolls is formed at least inpart of magnastrictive material operated in a pulsating magnetic fieldfrom a source adjacent the mill. In the practice of our invention it ispreferred that the vibrational force be introduced in such manner as tocause successive rapid expansion and contraction of the roll as itrotates in contact with the work.

In the foregoing general description of our invention we have set outcertain objects, purposes and advantages. Other objects, purposes andadvantages will be apparent ICC from the following description and theaccompanying drawings in which:

FIG. l is a front elevation of a two high mill embodying our invention;

FIG. 2 is a front elevation of a four high mill embodying our invention;

FIG. 3 is a front elevation of a second embodiment of a two high millembodying the subject of our invention; and

FIG. 4 is an enlarged fragmentary view of a preferred form of roll andfield inducing device.

Referring to the drawings we have illustrated in FIGS. 1 and 4 and a twohigh mill and roll therefore made up of a housing 10 of conventionaldesign with rolls 11 and 12 on opposite sides of a strip 13 forming apass line. Roll 11 is formed of magnastrictive material 14 surrounding acentral shaft 15 carrying bearing journals 16 at each end. A hardenedand ground alloy steel .sleeve 18 surrounds the magnastrictive material14 and provides the actual working surface of the roll. An electricalcoil 19 capable of providing a pulsating field is provided adjacent theroll 11. A frequency generator 20 or like electrical control isconnected to coil 19 and provides the electrical power to operate saidcoil. The operation of the frequency generator causes a magnetic fieldof pulsating character to be produced by the coil 19. This in turn actson the magnastrictive material 14 of the roll causing it to change itsphysical dimensions by enlarging and contracting on the diameter.

In FIG. 2, we have illustrated a second embodiment of our inventionapplied to a four high mill. Here a housing 30 of usual shape isprovided with work rolls 31 and 32 on opposite sides of a pass line andback up rolls 33 and 34 on opposite sides of the work rolls. One of theback up rolls 33 is formed in precisely the same manner as roll 11 ofFIG. l. Roll 33 is made up of a core 35 having journals 36 at each end.A magnastrictive material 37 surrounds the core 35 and an outer sleeve3S. A magnetic coil 39 and frequency generator 40 are placed adjacentthe roll 33 as in FIG. l.

In FIG. 3, we have illustrated a mill identical with that of FIG. lexcept that both work rolls are formed as shown in FIG. 4. Theconstruction and operation of the mill is identical with that of FIG. 1and like numerals with the prime sign are applied to like parts. Theonly difference between the mills is that both work rolls vibrate towork on the metal.

It will be obvious that in four high mills and the like, multihighmills, all back up rolls, all work rolls, or one back up roll or onework roll might be vibrated to produce a desired result and thesecombinations are contemplated by this invention.

The principal working functions of this invention are believed to residein our theory that when a magnetic field is placed with the magneticlines of force penetrating a magnastrictive material, this material willexpand and/or contract with the variance of this force, thereby when afrequency is passed through the coil a varying magnetic field will ensuein and about this coil, and since the magnastrictive material is in thisfield it will also be governed by the magnetic force, expanding andcontracting in unison with this field, thereby when the magnastrictivematerial is in the core of the roll and a sleeve of suitable rollingmaterial is placed on this core the sleeve will expand and contract dueto the magnastrictive material forcing it to expand and its ownelasticity will cause it to contract when the magnastrictive materialcontracts.

With the expansion and contraction of the magnastrictive material andthe Sleeve material in unison, we have accomplished the desired effectof vibrating the rolls.

This method is unique in the fact that the roll itself is pulsating anddoes not put undue strain on the bearings or bushings causingdeterioration. The amount of expansion can be governed by the magneticflux and by the diameter of the core, since the magnastrictive materialexpands or contracts in one direction only and the amount of expansionand contraction is greater with the greater length along its magneticaxes.

Another form of increasing the length of expansion and contraction is bypolarization of the material. This is done by applying a direct magneticeld of suicicntly high intensity for the value of the magnetic eld toremain above zero.

Various other means for inducing vibration into the roll may be usedsuch as by direct coupling of a transducer to the roll end. Theimportant thing to be observed is that the vibrational energy beintroduced to the roll through some means other than the bearings, i.e.outside the bearings and journals.

While We have illustrated and described certain preferred embodimentsand practices of our invention in the foregoing specification, it willbe understood that this invention may be otherwise embodied within thescope of the following claims.

We claim:

1. In a metal rolling mill having a housing, a plurality of rollsjournaled for rotation in said housing, at least one work roll being oneach side of a pass line, and means for introducing vibrational forceinto at least one of said rolls within the body of the roll, said meansexpanding Cil and contracting the roll radially to apply periodicpressure perpendicular to the plane of said pass line.

2. A rolling mill as claimed in claim 1 wherein the said one of saidrolls is formed at least in part by magnastrictive material providing apulsating magnetic field.

3. A rolling mill as claimed in claim 1 wherein more than one work rollis vibrated.

4. The method of rolling comprising the steps of:

(a) passing a body of metal between two rolls under pressure, and

(b) subjecting at least one of said rolls to vibrational forceintroduced into the roll within the body of the roll expanding andcontracting said roll radially to apply periodic pressure perpendicularto the plane of the pass line.

References Cited UNITED STATES PATENTS 2,995,050 8/1961 Karron et al.72205 3,096,672 7/1963` Jones 72-247X 3,401,547 9/19618 Hall et al.72-16 3,404,551 10/1968 Spisak 72F-l6 3,429,155 2/1969 Hines 72-16XFOREIGN PATENTS 133,324 10/1951 Sweden 29-VIBR MILTON S. MEHR, PrimaryExaminer

